Release 4.11 drivers/input/gameport/gameport.c

/*
 * Generic gameport layer
 *
 * Copyright (c) 1999-2002 Vojtech Pavlik
 * Copyright (c) 2005 Dmitry Torokhov
 */

/*
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/stddef.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/gameport.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/sched.h>	/* HZ */
#include <linux/mutex.h>
#include <linux/timekeeping.h>

/*#include <asm/io.h>*/

MODULE_AUTHOR("Vojtech Pavlik <vojtech@ucw.cz>");
MODULE_DESCRIPTION("Generic gameport layer");
MODULE_LICENSE("GPL");


static bool use_ktime = true;
module_param(use_ktime, bool, 0400);
MODULE_PARM_DESC(use_ktime, "Use ktime for measuring I/O speed");

/*
 * gameport_mutex protects entire gameport subsystem and is taken
 * every time gameport port or driver registrered or unregistered.
 */
static DEFINE_MUTEX(gameport_mutex);

static LIST_HEAD(gameport_list);


static struct bus_type gameport_bus;

static void gameport_add_port(struct gameport *gameport);
static void gameport_attach_driver(struct gameport_driver *drv);
static void gameport_reconnect_port(struct gameport *gameport);
static void gameport_disconnect_port(struct gameport *gameport);

#if defined(__i386__)

#include <linux/i8253.h>


#define DELTA(x,y)      ((y)-(x)+((y)<(x)?1193182/HZ:0))

#define GET_TIME(x)     do { x = get_time_pit(); } while (0)



static unsigned int get_time_pit(void)
{
	unsigned long flags;
	unsigned int count;

	raw_spin_lock_irqsave(&i8253_lock, flags);
	outb_p(0x00, 0x43);
	count = inb_p(0x40);
	count |= inb_p(0x40) << 8;
	raw_spin_unlock_irqrestore(&i8253_lock, flags);

	return count;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Vojtech Pavlik
57
96.61%
1
50.00%
Thomas Gleixner
2
3.39%
1
50.00%
Total
59
100.00%
2
100.00%

#endif



/*
 * gameport_measure_speed() measures the gameport i/o speed.
 */



static int gameport_measure_speed(struct gameport *gameport)
{
	unsigned int i, t, tx;
	u64 t1, t2, t3;
	unsigned long flags;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	tx = ~0;

	for (i = 0; i < 50; i++) {
		local_irq_save(flags);
		t1 = ktime_get_ns();
		for (t = 0; t < 50; t++)
			gameport_read(gameport);
		t2 = ktime_get_ns();
		t3 = ktime_get_ns();
		local_irq_restore(flags);
		udelay(i * 10);
		t = (t2 - t1) - (t3 - t2);
		if (t < tx)
			tx = t;
	}

	gameport_close(gameport);
	t = 1000000 * 50;
	if (tx)
		t /= tx;
	return t;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Takashi Iwai
150
93.75%
1
50.00%
Linus Torvalds (pre-git)
10
6.25%
1
50.00%
Total
160
100.00%
2
100.00%



static int old_gameport_measure_speed(struct gameport *gameport)
{
#if defined(__i386__)

	unsigned int i, t, t1, t2, t3, tx;
	unsigned long flags;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	tx = 1 << 30;

	for(i = 0; i < 50; i++) {
		local_irq_save(flags);
		GET_TIME(t1);
		for (t = 0; t < 50; t++) gameport_read(gameport);
		GET_TIME(t2);
		GET_TIME(t3);
		local_irq_restore(flags);
		udelay(i * 10);
		if ((t = DELTA(t2,t1) - DELTA(t3,t2)) < tx) tx = t;
	}

	gameport_close(gameport);
	return 59659 / (tx < 1 ? 1 : tx);

#elif defined (__x86_64__)

	unsigned int i, t;
	unsigned long tx, t1, t2, flags;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	tx = 1 << 30;

	for(i = 0; i < 50; i++) {
		local_irq_save(flags);
		t1 = rdtsc();
		for (t = 0; t < 50; t++) gameport_read(gameport);
		t2 = rdtsc();
		local_irq_restore(flags);
		udelay(i * 10);
		if (t2 - t1 < tx) tx = t2 - t1;
	}

	gameport_close(gameport);
	return (this_cpu_read(cpu_info.loops_per_jiffy) *
		(unsigned long)HZ / (1000 / 50)) / (tx < 1 ? 1 : tx);

#else

	unsigned int j, t = 0;

	if (gameport_open(gameport, NULL, GAMEPORT_MODE_RAW))
		return 0;

	j = jiffies; while (j == jiffies);
	j = jiffies; while (j == jiffies) { t++; gameport_read(gameport); }

	gameport_close(gameport);
	return t * HZ / 1000;

#endif
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Linus Torvalds (pre-git)
192
49.74%
1
11.11%
Vojtech Pavlik
164
42.49%
2
22.22%
Gabriel Devenyi
10
2.59%
1
11.11%
Takashi Iwai
10
2.59%
1
11.11%
Andrew Lutomirski
6
1.55%
2
22.22%
Christoph Lameter
3
0.78%
1
11.11%
Mike Travis
1
0.26%
1
11.11%
Total
386
100.00%
9
100.00%



void gameport_start_polling(struct gameport *gameport)
{
	spin_lock(&gameport->timer_lock);

	if (!gameport->poll_cnt++) {
		BUG_ON(!gameport->poll_handler);
		BUG_ON(!gameport->poll_interval);
		mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
	}

	spin_unlock(&gameport->timer_lock);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
69
100.00%
1
100.00%
Total
69
100.00%
1
100.00%


EXPORT_SYMBOL(gameport_start_polling);



void gameport_stop_polling(struct gameport *gameport)
{
	spin_lock(&gameport->timer_lock);

	if (!--gameport->poll_cnt)
		del_timer(&gameport->poll_timer);

	spin_unlock(&gameport->timer_lock);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
42
100.00%
1
100.00%
Total
42
100.00%
1
100.00%


EXPORT_SYMBOL(gameport_stop_polling);



static void gameport_run_poll_handler(unsigned long d)
{
	struct gameport *gameport = (struct gameport *)d;

	gameport->poll_handler(gameport);
	if (gameport->poll_cnt)
		mod_timer(&gameport->poll_timer, jiffies + msecs_to_jiffies(gameport->poll_interval));
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
52
100.00%
1
100.00%
Total
52
100.00%
1
100.00%

/*
 * Basic gameport -> driver core mappings
 */



static int gameport_bind_driver(struct gameport *gameport, struct gameport_driver *drv)
{
	int error;

	gameport->dev.driver = &drv->driver;
	if (drv->connect(gameport, drv)) {
		gameport->dev.driver = NULL;
		return -ENODEV;
	}

	error = device_bind_driver(&gameport->dev);
	if (error) {
		dev_warn(&gameport->dev,
			 "device_bind_driver() failed for %s (%s) and %s, error: %d\n",
			gameport->phys, gameport->name,
			drv->description, error);
		drv->disconnect(gameport);
		gameport->dev.driver = NULL;
		return error;
	}

	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
93
80.17%
6
85.71%
Linus Torvalds (pre-git)
23
19.83%
1
14.29%
Total
116
100.00%
7
100.00%



static void gameport_find_driver(struct gameport *gameport)
{
	int error;

	error = device_attach(&gameport->dev);
	if (error < 0)
		dev_warn(&gameport->dev,
			 "device_attach() failed for %s (%s), error: %d\n",
			 gameport->phys, gameport->name, error);
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Randy Dunlap
24
48.00%
1
20.00%
Dmitry Torokhov
17
34.00%
3
60.00%
Linus Torvalds (pre-git)
9
18.00%
1
20.00%
Total
50
100.00%
5
100.00%

/*
 * Gameport event processing.
 */


enum gameport_event_type {
	
GAMEPORT_REGISTER_PORT,
	
GAMEPORT_ATTACH_DRIVER,
};


struct gameport_event {
	
enum gameport_event_type type;
	
void *object;
	
struct module *owner;
	
struct list_head node;
};

static DEFINE_SPINLOCK(gameport_event_lock);	/* protects gameport_event_list */
static LIST_HEAD(gameport_event_list);



static struct gameport_event *gameport_get_event(void)
{
	struct gameport_event *event = NULL;
	unsigned long flags;

	spin_lock_irqsave(&gameport_event_lock, flags);

	if (!list_empty(&gameport_event_list)) {
		event = list_first_entry(&gameport_event_list,
					 struct gameport_event, node);
		list_del_init(&event->node);
	}

	spin_unlock_irqrestore(&gameport_event_lock, flags);
	return event;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
68
94.44%
3
60.00%
Linus Torvalds
2
2.78%
1
20.00%
Adrian Bunk
2
2.78%
1
20.00%
Total
72
100.00%
5
100.00%



static void gameport_free_event(struct gameport_event *event)
{
	module_put(event->owner);
	kfree(event);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
23
100.00%
1
100.00%
Total
23
100.00%
1
100.00%



static void gameport_remove_duplicate_events(struct gameport_event *event)
{
	struct gameport_event *e, *next;
	unsigned long flags;

	spin_lock_irqsave(&gameport_event_lock, flags);

	list_for_each_entry_safe(e, next, &gameport_event_list, node) {
		if (event->object == e->object) {
			/*
                         * If this event is of different type we should not
                         * look further - we only suppress duplicate events
                         * that were sent back-to-back.
                         */
			if (event->type != e->type)
				break;

			list_del_init(&e->node);
			gameport_free_event(e);
		}
	}

	spin_unlock_irqrestore(&gameport_event_lock, flags);
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
88
100.00%
2
100.00%
Total
88
100.00%
2
100.00%



static void gameport_handle_events(struct work_struct *work)
{
	struct gameport_event *event;

	mutex_lock(&gameport_mutex);

	/*
         * Note that we handle only one event here to give swsusp
         * a chance to freeze kgameportd thread. Gameport events
         * should be pretty rare so we are not concerned about
         * taking performance hit.
         */
	if ((event = gameport_get_event())) {

		switch (event->type) {

		case GAMEPORT_REGISTER_PORT:
			gameport_add_port(event->object);
			break;

		case GAMEPORT_ATTACH_DRIVER:
			gameport_attach_driver(event->object);
			break;
		}

		gameport_remove_duplicate_events(event);
		gameport_free_event(event);
	}

	mutex_unlock(&gameport_mutex);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
80
100.00%
2
100.00%
Total
80
100.00%
2
100.00%

static DECLARE_WORK(gameport_event_work, gameport_handle_events);



static int gameport_queue_event(void *object, struct module *owner,
				enum gameport_event_type event_type)
{
	unsigned long flags;
	struct gameport_event *event;
	int retval = 0;

	spin_lock_irqsave(&gameport_event_lock, flags);

	/*
         * Scan event list for the other events for the same gameport port,
         * starting with the most recent one. If event is the same we
         * do not need add new one. If event is of different type we
         * need to add this event and should not look further because
         * we need to preserve sequence of distinct events.
         */
	list_for_each_entry_reverse(event, &gameport_event_list, node) {
		if (event->object == object) {
			if (event->type == event_type)
				goto out;
			break;
		}
	}

	event = kmalloc(sizeof(struct gameport_event), GFP_ATOMIC);
	if (!event) {
		pr_err("Not enough memory to queue event %d\n", event_type);
		retval = -ENOMEM;
		goto out;
	}

	if (!try_module_get(owner)) {
		pr_warning("Can't get module reference, dropping event %d\n",
			   event_type);
		kfree(event);
		retval = -EINVAL;
		goto out;
	}

	event->type = event_type;
	event->object = object;
	event->owner = owner;

	list_add_tail(&event->node, &gameport_event_list);
	queue_work(system_long_wq, &gameport_event_work);

out:
	spin_unlock_irqrestore(&gameport_event_lock, flags);
	return retval;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
189
100.00%
4
100.00%
Total
189
100.00%
4
100.00%

/*
 * Remove all events that have been submitted for a given object,
 * be it a gameport port or a driver.
 */


static void gameport_remove_pending_events(void *object)
{
	struct gameport_event *event, *next;
	unsigned long flags;

	spin_lock_irqsave(&gameport_event_lock, flags);

	list_for_each_entry_safe(event, next, &gameport_event_list, node) {
		if (event->object == object) {
			list_del_init(&event->node);
			gameport_free_event(event);
		}
	}

	spin_unlock_irqrestore(&gameport_event_lock, flags);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
73
100.00%
3
100.00%
Total
73
100.00%
3
100.00%

/*
 * Destroy child gameport port (if any) that has not been fully registered yet.
 *
 * Note that we rely on the fact that port can have only one child and therefore
 * only one child registration request can be pending. Additionally, children
 * are registered by driver's connect() handler so there can't be a grandchild
 * pending registration together with a child.
 */


static struct gameport *gameport_get_pending_child(struct gameport *parent)
{
	struct gameport_event *event;
	struct gameport *gameport, *child = NULL;
	unsigned long flags;

	spin_lock_irqsave(&gameport_event_lock, flags);

	list_for_each_entry(event, &gameport_event_list, node) {
		if (event->type == GAMEPORT_REGISTER_PORT) {
			gameport = event->object;
			if (gameport->parent == parent) {
				child = gameport;
				break;
			}
		}
	}

	spin_unlock_irqrestore(&gameport_event_lock, flags);
	return child;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
92
100.00%
1
100.00%
Total
92
100.00%
1
100.00%

/*
 * Gameport port operations
 */



static ssize_t gameport_description_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct gameport *gameport = to_gameport_port(dev);

	return sprintf(buf, "%s\n", gameport->name);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
36
85.71%
1
33.33%
Yani Ioannou
5
11.90%
1
33.33%
Greg Kroah-Hartman
1
2.38%
1
33.33%
Total
42
100.00%
3
100.00%

static DEVICE_ATTR(description, S_IRUGO, gameport_description_show, NULL);



static ssize_t drvctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	struct gameport *gameport = to_gameport_port(dev);
	struct device_driver *drv;
	int error;

	error = mutex_lock_interruptible(&gameport_mutex);
	if (error)
		return error;

	if (!strncmp(buf, "none", count)) {
		gameport_disconnect_port(gameport);
	} else if (!strncmp(buf, "reconnect", count)) {
		gameport_reconnect_port(gameport);
	} else if (!strncmp(buf, "rescan", count)) {
		gameport_disconnect_port(gameport);
		gameport_find_driver(gameport);
	} else if ((drv = driver_find(buf, &gameport_bus)) != NULL) {
		gameport_disconnect_port(gameport);
		error = gameport_bind_driver(gameport, to_gameport_driver(drv));
	} else {
		error = -EINVAL;
	}

	mutex_unlock(&gameport_mutex);

	return error ? error : count;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
168
94.38%
2
40.00%
Yani Ioannou
5
2.81%
1
20.00%
Arjan van de Ven
4
2.25%
1
20.00%
Greg Kroah-Hartman
1
0.56%
1
20.00%
Total
178
100.00%
5
100.00%

static DEVICE_ATTR_WO(drvctl);


static struct attribute *gameport_device_attrs[] = {
	&dev_attr_description.attr,
	&dev_attr_drvctl.attr,
	NULL,
};

ATTRIBUTE_GROUPS(gameport_device);



static void gameport_release_port(struct device *dev)
{
	struct gameport *gameport = to_gameport_port(dev);

	kfree(gameport);
	module_put(THIS_MODULE);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
31
100.00%
1
100.00%
Total
31
100.00%
1
100.00%



void gameport_set_phys(struct gameport *gameport, const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	vsnprintf(gameport->phys, sizeof(gameport->phys), fmt, args);
	va_end(args);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
50
100.00%
1
100.00%
Total
50
100.00%
1
100.00%


EXPORT_SYMBOL(gameport_set_phys);

/*
 * Prepare gameport port for registration.
 */


static void gameport_init_port(struct gameport *gameport)
{
	static atomic_t gameport_no = ATOMIC_INIT(-1);

	__module_get(THIS_MODULE);

	mutex_init(&gameport->drv_mutex);
	device_initialize(&gameport->dev);
	dev_set_name(&gameport->dev, "gameport%lu",
			(unsigned long)atomic_inc_return(&gameport_no));
	gameport->dev.bus = &gameport_bus;
	gameport->dev.release = gameport_release_port;
	if (gameport->parent)
		gameport->dev.parent = &gameport->parent->dev;

	INIT_LIST_HEAD(&gameport->node);
	spin_lock_init(&gameport->timer_lock);
	init_timer(&gameport->poll_timer);
	gameport->poll_timer.function = gameport_run_poll_handler;
	gameport->poll_timer.data = (unsigned long)gameport;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
128
90.14%
3
42.86%
Randy Dunlap
8
5.63%
1
14.29%
Aniroop Mathur
2
1.41%
1
14.29%
Kay Sievers
2
1.41%
1
14.29%
Arjan van de Ven
2
1.41%
1
14.29%
Total
142
100.00%
7
100.00%

/*
 * Complete gameport port registration.
 * Driver core will attempt to find appropriate driver for the port.
 */


static void gameport_add_port(struct gameport *gameport)
{
	int error;

	if (gameport->parent)
		gameport->parent->child = gameport;

	gameport->speed = use_ktime ?
		gameport_measure_speed(gameport) :
		old_gameport_measure_speed(gameport);

	list_add_tail(&gameport->node, &gameport_list);

	if (gameport->io)
		dev_info(&gameport->dev, "%s is %s, io %#x, speed %dkHz\n",
			 gameport->name, gameport->phys, gameport->io, gameport->speed);
	else
		dev_info(&gameport->dev, "%s is %s, speed %dkHz\n",
			gameport->name, gameport->phys, gameport->speed);

	error = device_add(&gameport->dev);
	if (error)
		dev_err(&gameport->dev,
			"device_add() failed for %s (%s), error: %d\n",
			gameport->phys, gameport->name, error);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
115
79.86%
2
50.00%
Randy Dunlap
22
15.28%
1
25.00%
Takashi Iwai
7
4.86%
1
25.00%
Total
144
100.00%
4
100.00%

/*
 * gameport_destroy_port() completes deregistration process and removes
 * port from the system
 */


static void gameport_destroy_port(struct gameport *gameport)
{
	struct gameport *child;

	child = gameport_get_pending_child(gameport);
	if (child) {
		gameport_remove_pending_events(child);
		put_device(&child->dev);
	}

	if (gameport->parent) {
		gameport->parent->child = NULL;
		gameport->parent = NULL;
	}

	if (device_is_registered(&gameport->dev))
		device_del(&gameport->dev);

	list_del_init(&gameport->node);

	gameport_remove_pending_events(gameport);
	put_device(&gameport->dev);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
103
100.00%
2
100.00%
Total
103
100.00%
2
100.00%

/*
 * Reconnect gameport port and all its children (re-initialize attached devices)
 */


static void gameport_reconnect_port(struct gameport *gameport)
{
	do {
		if (!gameport->drv || !gameport->drv->reconnect || gameport->drv->reconnect(gameport)) {
			gameport_disconnect_port(gameport);
			gameport_find_driver(gameport);
			/* Ok, old children are now gone, we are done */
			break;
		}
		gameport = gameport->child;
	} while (gameport);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Dmitry Torokhov
62
100.00%
1
100.00%
Total
62
100.00%
1
100.00%

/*
 * gameport_disconnect_port() unbinds a port from its driver. As a side effect
 * all child ports are unbound and destroyed.
 */


static void gameport_disconnect_port(struct gameport *gameport)
{
	struct gameport *s, *parent;

	if